Composite structure with a uniform crystal orientation and the method of controlling the crystal orientation of one such structure

ABSTRACT

This invention relates to a process for controlling the orientation of secondary structures (A 1 , A 2 ) with at least a crystalline part during the transfer of secondary structures from a primary structure (A) on which the secondary structures have an initial crystalline orientation identical to the orientation of the primary structure, onto at least one support structure (B), the process comprising:  
     a) the formation of at least one orientation mark (Va, Va 1 , Va 2 ) when the secondary structures are fixed to the primary structure (A), the mark having an arbitrary orientation with respect to the said initial crystalline orientation, but identical for each secondary structure, and  
     b) when a set of secondary structures is transferred onto at least one support structure (B), an arrangement of the secondary structures so that their orientation marks can be oriented in a controlled manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority based on International PatentApplication No. PCT/FRO2/02136, entitled, “Composite Structure WithUniform Crystalline Orientation And Process For Controlling TheCrystalline Orientation of Such A Structure” by Franck Fournel, BernardAspar and Hubert Moriceau, which claims priority of French ApplicationNo. 01 08257, filed on Jun. 22, 2001.

TECHNICAL FIELD

[0002] This invention relates to a composite structure with controlledcrystalline orientation and a process for controlling the crystallineorientation of such a structure. It also relates to a process for makingsuch a structure.

[0003] The invention is used in various applications, for example in thefields of microelectronics, integrated optics and micro-mechanics, andin particular is designed to supply large substrates with propertiesappropriate for their destination.

[0004] For example, the invention may be used to make compositesubstrates of the Si/Si, Si/Ge, Ge/Ge, Si/SiC, SiC/SiC, SiC/Ge types. Itis also suitable for any other homogenous or heterogeneous combinationof III-IV or II-VI semiconductors, diamond, silicon carbide,superconductors, magnetic materials, piezo-electric materials or moregenerally materials in textured polycrystalline or monocrystalline form.Crystalline materials may be combined with each other or with amorphousmaterials, or ceramic or plastic materials.

STATE OF PRIOR ART

[0005] Substrates, and particularly substrates used in the technicalfields mentioned above, are more and more frequently compositesubstrates that comprise a support and a superficial part in which thecomponents are made. A number of techniques are known for making suchcomposite substrates.

[0006] These techniques consist essentially of transferring “secondarystructure” layers, which are usually thin, from a primary or “donating”structure to a support or “receiving” structure.

[0007] Separation of the thin layer (or secondary structure) from theprimary structure takes place by cutting, cleavage or fracture, awell-known technique described in document (1) for which the referencesare given at the end of the description. For example, this techniqueconsists of forming a buried weakening layer in the primary structureand fracturing the primary structure along this layer to detach thesecondary structure from it.

[0008] The cut, cleavage or fracture can be assisted by applyingmechanical or thermal stresses. Tools for applying tension, shear,etching or peeling treatments, application of a fluid jet, and the useof a cutting laser are all means that can be used to provoke orfacilitate separation of secondary structures from the primarystructure.

[0009] An illustration is given in documents (2) and (3), the referencesof which are also given at the end of this description.

[0010] The secondary structures are then transferred onto the supportstructures to which they are bonded. This operation may make use ofdifferent bonding techniques with or without an adhesive substance, forexample molecular bonding.

[0011] Transfer techniques for secondary structures are well known inthemselves and are also illustrated in documents (4) to (7), thereferences of which are given at the end of this description.

[0012] One important parameter for transferring layers of crystallinematerial or more generally for transferring structures with at least onecrystalline part, is the alignment of crystalline networks.

[0013] There are two alignments, firstly alignment between crystallinenetworks of transferred secondary structures, and secondly alignment ofthe crystalline network of secondary structures with the crystallinenetwork of the support structure.

[0014] For the purposes of this document, alignment does not necessarilymean co-linearity of crystalline networks, but refers to control overthe angle between the networks.

[0015] The “twist” angle is defined as being the angle of rotationbetween two crystalline networks about an axis perpendicular to thesurface of the samples considered.

[0016] The “tilt” angle is defined as being the minimum rotation anglemade about an axis parallel to the surface to align the vector normal tothis surface with one of the three axes of the crystalline network of acrystalline layer of the structure. The surface tilt angles are used todefine an “interface tilt” angle between two crystalline layers, each ofwhich has a surface tilt angle. The values of the “twist” and “interfacetilt” angles are defined such that the combination of these tworotations can align the two crystalline networks. In other words, thereis a rotation between two crystalline structures to pass from onecrystalline network to the other and that can be broken down into tworotations, one parallel and one perpendicular to the two surfacesbetween the two structures to be assembled. These rotations correspondto the interface twist and tilt angles. The angles can be definedbetween two crystalline structures one on top of the other or one at theside of the other.

[0017] Document (8) describes techniques for revealing the crystallineaxes of a structure. These techniques involve chemical revelation of theaxes and there are technical difficulties in applying them. Furthermore,this document does not provide any information about how to control theinterface tilt or to make a controlled paving in the crystallographicdirection. The need for a useful surface and the large amount of timeare the main obstacles to revelation of crystalline axes. Furthermore,the precision at which the orientation of axes is known is usually notbetter than 0.1°.

[0018] Finally, it is possible to reveal crystalline axes by makingX-ray measurements. Apart from the fact that these X-ray measurementstake time, they are difficult to apply and their use is limited for thinfilms.

PRESENTATION OF THE INVENTION

[0019] The purpose of the invention is to propose a process for makingcomposite structures comprising the transfer of at least one secondarystructure derived from a primary structure onto a support structure,without the limitations mentioned above.

[0020] Another purpose is to propose a precise and simple process forcontrolling the orientation of secondary structures with respect to eachother, or with respect to the support structure.

[0021] In order to achieve these purposes, the invention relates to aprocess for controlling the orientation of secondary structures with atleast a crystalline part during the transfer of secondary structuresfrom a primary structure on which the secondary structures have aninitial crystalline orientation identical to the orientation of theprimary structure or with a known misalignment with respect to theprimary structure, onto at least one support structure. The processcomprises:

[0022] a) formation of at least one orientation mark on each secondarystructure when the secondary structures are fixed to the primarystructure, the mark having an arbitrary orientation with respect to thesaid initial crystalline orientation, but allowing relative orientationof the secondary structure, and

[0023] b) when secondary structures are transferred onto at least onesupport structure, an arrangement of the secondary structures so thattheir orientation marks can be oriented in a controlled manner.

[0024] If the secondary structures are monocrystalline, it is possibleto provide marks with an identical orientation for each secondarystructure.

[0025] A structure means an assembly formed from one or several layersthat may have at least a part made from a crystalline material(monocrystalline or polycrystalline). In its simplest expression, it maybe for example a unique crystalline layer that may or may not be coveredwith an amorphous layer or an amorphous layer covered by a crystallinelayer. Note also that the support structure does not necessarily have acrystalline part. More complex structures, such as multi-layerstructures, can also be selected.

[0026] Secondary structures may also be transferred on a single supportstructure or onto several such structures. In particular, the transfermay take place on several “daughter” support structures originating fromthe said same “mother” support structure. For example, this is the casewhen the “daughter” support structures are obtained by cutting,cleavage, or a fracture of a single crystal acting as a motherstructure.

[0027] These “daughter” support structures then act as supportstructures. At least one orientation mark can be formed on each“daughter” support structure when it is fixed to the “mother” supportstructure, enabling relative orientation of “daughter” supportstructures.

[0028] Orientation marks may be formed before the transfer, for examplesuch that after the transfer these marks are partly in the secondarystructure (or in “daughter” structures) and in the primary structure (orin the “mother” structure). Thus the marks in these two types ofstructures have the same orientation with respect to the crystallinestructure.

[0029] Marks may be made in one or several steps in the secondary (or“daughter”) and primary (or “mother”) structures. Steps for the transferand production of new marks can then be inserted. Advantageously, newmarks are made by using marks defined for the previous secondary (or“daughter”) structure.

[0030] A precise angular alignment is thus possible during the transferwithout it being necessary to include a step to reveal the crystallinedirections. It is then easy to make an alignment from simple orientationmarks. This alignment may be made between the secondary structures oreven between each secondary structure and the support structure orbetween each secondary structure and “daughter” support structures.

[0031] Preferably, orientation marks are simple geometric shapes such asparallel lines, squares or any other form that may make an angularmarking. In one improved embodiment of the process, the orientationmarks may be graduated scales. This type of graduated scale is known initself. They enable particularly precise angular adjustment. The marksmay also be composed of the edges of secondary (or “daughter”)structures.

[0032] For example, orientation marks may be made by lithography andetching or by laser drilling.

[0033] In particular, controlling the orientation of the orientationmarks during transfer enables determination of the alignment ofcrystalline networks that existed in the primary structure. Furthermore,this does not require absolute knowledge of crystalline directions.

[0034] For example, the operation that consists of orienting thetransferred secondary structures with respect to each other duringtransfer may include an angular alignment. It may also consist ofrespecting an angular offset given with respect to the orientation markof one of the secondary structures used as the test structure. It mayalso consist of respecting an angular offset with respect to at leastone other mark, for example fixed onto the support structure or the“daughter” support structures.

[0035] When the support structure itself is crystalline, or at leastcomprises a crystalline part, it may be desirable to orient thesecondary structures with respect to each other, and also with respectto the crystalline orientation of the support structure or the“daughter” support structures.

[0036] In this case, after at least a first secondary structure has beentransferred from a primary structure onto a support structure with atleast one crystalline part, step b may include the determination of atleast one offset angle of the crystalline orientations of thecrystalline parts of the first transferred secondary structure and thesupport structure, and then when the subsequent secondary structures aretransferred, adjustment of the arrangement of the marks on the supportas a function of the determined offset.

[0037] The first transferred secondary structure used as a test may beoriented arbitrarily on the support structure.

[0038] The secondary test structure and any “daughter” structure mayalso be used to determine the offset. The orientation of the othersecondary structures on one or the other “daughter” structures is thenadjusted.

[0039] Note that in this process, neither knowledge of the crystallineorientation of the support structure nor knowledge of the secondarystructures is necessary. All that is determined is the offset betweenthe orientation of the crystalline structures, not an absoluteorientation.

[0040] For example, the offset angle may be determined using a techniquefor measuring interface dislocations between the secondary structure andthe support structure, for example by electronic transmission microscopyor by an X-ray technique for measuring an offset between theorientations of the crystalline parts. Further information about thissubject is given in document (9), the references of which are includedat the end of this description.

[0041] Other measurement techniques by chemical revealing, by optical oracoustic method or any other method sensitive to a crystalline offset,may also be used.

[0042] Compensation of crystalline orientation offsets determinedbetween the first transferred structure(s) and the support structure(s)may for example take place by keeping a constant offset between theorientation of the marks of the subsequent secondary structures and themark of the secondary test structure. The twist angles can thus becancelled and the tilt angles can be reduced or also cancelled.Cancellation or compensation of the twist or tilt angle may be appliedbetween secondary structures, or between secondary structures and thesupport structure, or between secondary structures and “daughter”support structures.

[0043] The invention also relates to a process for manufacturingcomposite structures comprising secondary structures fixed to at leastone support structure. The process comprises:

[0044] delimitation of secondary structures with at least onecrystalline part in a primary structure and

[0045] transfer of secondary structures onto a support structure with atleast one crystalline part, controlling the relative orientation ofsecondary structures and the support structure in accordance with theprocess described above.

[0046] Delimitation of secondary structures in the primary structureenables them to be transferred individually. According to one feature,the secondary structures may be delimited in the primary structure by aburied layer. For example, it may be a layer formed by implantation ofhydrogen or rare gases. It can delimit a secondary structure each timeand detach it from the primary structure using a fracture techniquedescribed in document (1) mentioned above.

[0047] Secondary structures can be fixed on the support structure bybonding with or without the addition of material (adhesive). Forexample, it may be a hydrophilic, hydrophobic, eutectic or anodicmolecular bonding.

[0048] When secondary structures are fixed to a support structure, alayer of material may be formed on the free surface of these compositestructures, for example by epitaxy. The crystalline part of thesecondary structures is then used as a growth germ. If the secondarystructures used as growth germs are arranged to be adjacent to eachother, a layer formed by epitaxy may occupy a relatively large surfacearea. For example, the layer formed by epitaxy may cover a compositestructure in the form of a 200 mm diameter disk. This can beparticularly advantageous for III-V or II-VI semiconducting materialssuch as GaAs, InP or SIC. The diameters of monocrystals available forthese materials at the moment are of the order of 100 mm and 50 mmrespectively.

[0049] After epitaxy, the structure obtained may be used as a primarystructure to repeat the process. The secondary structures do notnecessarily cover the entire surface of the support structure.Advantageously, there may be one or several disorientations between thesurface of the secondary structures and the surface of the support.During epitaxy is done on all structures, this can cause the appearanceof grain boundaries at the junction between part of the depositedmaterial for which the orientation is conform with the orientation ofthe surface of the secondary structure on which it began to grow, andpart of the deposited material for which the orientation is conform withthe orientation of the surface of the support structure on which itbegan to grow. This may be very useful for creating superconductingjunctions at grain boundaries simply by using secondary structures.

[0050] The invention may also be used to make compliant substrates orpseudo-substrates. A pseudo-substrate is a substrate for which the meshparameter is adapted to a material to be deposited by epitaxy, and acompliant substrate is a substrate that can accommodate epitaxy ofmaterials with indifferent mesh parameters. In this case, the epitaxymay be done without inducing any defects, for example dislocations.

[0051] Finally, the invention relates to a composite structure with afirst structure fixed to at least one second structure in which at leastone of the first and second structures has uniformly orientedorientation marks. In particular, the orientation marks may be arrangedon each side of a bonding interface.

[0052] Other advantages and specificities of the invention will becomeclear from the following description with reference to the figures inthe appended drawings. This description is given purely for illustrativepurposes and is in no way limitative.

BRIEF DESCRIPTION OF THE FIGURES

[0053] FIGS. 1 to 3 are top views of substrates showing transfer of thinlayers with control of the crystalline orientation of these layers inaccordance with the invention.

[0054] FIGS. 4 to 6 are top views of first and second substrates andillustrate the assembly of these substrates according to the invention.

[0055] FIGS. 7 to 9 are diagrammatic representations of substrates andillustrate a technique for the assembly of several substrates in pairs,respecting their crystalline orientation in accordance with theinvention.

[0056]FIG. 10 shows the paving of a first substrate with several secondsubstrates sampled on the same monocrystal in accordance with theinvention.

[0057]FIG. 11 shows donating and receiving substrates and illustrates aniterative application of the process according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0058] In the following description, identical, similar or equivalentparts of the different figures have the same references. Furthermore,the different parts are not necessarily shown at the same scale forreasons of clarity in the figures.

[0059] In a first embodiment of the invention, a first substrate A madeof crystalline germanium with a diameter of 100 mm is used as a primarystructure. A second substrate B made of crystalline silicon with adiameter of 200 mm is used as a support structure.

[0060] In a first step, an orientation mark Va is made in the form of apair of graduated scales etched on a part of the surface of the firstsubstrate. Two orientation marks Vb1, Vb2 of the same type as the markVa on the first substrate are also made on the second substrate B. Themarks on the second substrate are angularly centred and are aligned onthe same diameter. They are made at distinct locations, and enablesubsequent superposition with orientation marks on the first substrate(Va) when the secondary structures are bonded. The marks are made byphotolithography and etching.

[0061] A first secondary structure, in the event a thin film A1, isdetached from the first substrate A along a weakened zone, not shown,made by ionic implantation. The thin film A1 on which the orientationmark Va is marked, is transferred to the second substrate B in theregion of the first orientation mark Vb1.

[0062] The transfer illustrated in FIG. 2 takes place without anyorientation precaution.

[0063] An offset between the crystalline orientation of the secondsubstrate B and the thin layer A1 is then measured. This operation maytake place by sampling a test piece comprising a part of the twostructures B and A1 in contact. The interface dislocations can bemeasured in a known manner, for example by TEM microscopy or by X-rays,and the interface dislocations can be measured and used to deduce thecrystalline disorientation between B and A.

[0064] A second thin layer A2, on which an orientation mark Va2 is madeidentical to the mark Va1 of the first thin layer, is then detached fromthe same first substrate A and is also transferred onto the secondsubstrate B. As shown in FIG. 3, the transfer takes place in the regionof the second orientation mark Vb2 on this substrate, in other wordsadjacent to the first thin layer.

[0065] Advantageously, the mark Va1 that remained on the support isused, prolonging it to form the mark Va2. In this case, and although thecrystalline orientation of the first substrate A is unknown, it is knownthat the second orientation mark Va2 has the same angular differencefrom the crystalline orientation of the second thin layer A2 as theangular difference between the first orientation mark Va1 from thecrystalline orientation of the first thin layer A1.

[0066] Due to the orientation marks and knowledge of the orientationoffset between the crystalline structures of substrate B and the firstthin layer A1, the second thin layer A2 can be rotated until therequired twist angle is obtained. The fact that secondary structures arelifted off by this method can give almost identical surface tilts forthe secondary structures. Furthermore, since the tilt angle of thebonding interface depends on the twist angle, the tilt angle can becalculated as a function of the twist angle.

[0067] In particular, the second thin layer A2 may be oriented so as toreduce or even eliminate the difference between its orientation and theorientation of the support substrate B. This is done by rotating thesecond thin layer A2 and/or the support B about an axis perpendicular tothe bonding plane.

[0068] The use of orientation marks in the form of pairs of graduatedscales is a means of controlling alignments or twist angles or tiltangles with a precision of the order of one hundredth of a degree.Optical microscopy methods can be used to make this alignment. Thewavelength is chosen to pass through at least one of the secondary orsupport structures when at least one mark is located at the bondinginterface.

[0069] A second example embodiment of the process is illustrated inFIGS. 4 to 6. For simplification reasons, parts corresponding to partsin the previous figures are marked with the same references, even iftheir shape is slightly different.

[0070] In FIG. 4, the primary structure is a wafer of monocrystallinesilicon A and the support structure is a wafer of monocrystallinesilicon B. Two orientation marks index 1 and 2 are made at distinctlocations on each of these wafers, mutually defining a fixed relativeposition identical for each wafer. These are the pairs of squares Va1,Vb1, and pairs of graduated scales Va2 and Vb2 respectively.

[0071] The first wafer A is then cut into two parts A1 and A2, markedwith the orientation marks Va1 and Va2 respectively. As shown in FIG. 5,the part A1 marked with the orientation marks in the form of two squaresis transferred and bonded on wafer B, making the squares coincide withthe squares of the first orientation mark Vb1 on the second wafer B.

[0072] After this first transfer, the twist and tilt interface anglesimposed by bonding the first part A1 onto the wafer B are determined asin the first example.

[0073] Since the graduated scales, in other words the second orientationmarks Va2 and Vb2 were initially fixed in relation to the firstorientation marks, in other words to the squares, the relativedisorientation of the graduated scales is known; it is the offsetdetermined between the crystalline directions of the first part A1 andthe wafer B (twist) and the interface tilt.

[0074] When the second part A2 is transferred as illustrated in FIG. 6,it is then possible to control the twist angle and the interface tiltangle since the interface tilt angle depends on the twist angle, or atleast to adjust it to a determined value by turning the second part A2about an axis perpendicular to its bonding plane. The first and secondparts in FIGS. 5 and 6 are cross-hatched to make it easier to understandthe figures.

[0075] A third example embodiment of the process is illustrated in FIGS.7 to 9. In this example, the secondary structures A1, A2, . . . areobtained by successive separation of a first substrate A used as aprimary structure. The secondary structures are individually transferredonto a corresponding number of support structures B1, B2, . . . ,obtained by successive separation of a second substrate B. Thesubstrates A and B are shown in FIG. 7.

[0076] The verniers Va and Vb used as orientation marks are etched inthe first and second substrates A and B at a sufficient depth to belocated identically on all structures A1, A2, . . . , B1, B2, . . . ,obtained subsequently by cleavage.

[0077] A first assembly of structures A1 and B1 originating from thefirst and second substrates A and B is made as shown in FIG. 8, bymaking an angular alignment of the verniers Va and Vb.

[0078] After assembling the two structures, the offset of theircrystalline orientation is measured as in the previous examples.

[0079] Then, as shown in FIG. 9, the subsequent structures A2, B2, . . ., are assembled by providing a given angular offset in the alignment oftheir verniers Va and Vb. This offset may be selected to control theoffset between the crystalline orientations.

[0080] When other subsequent structures originating from the first andsecond substrates A and B are assembled subsequently, an angular offsetbetween their verniers Va and Vb is also controlled, which may beidentical to the offset of the structures A2 and B2 in FIG. 9, or it maybe different.

[0081] Another example according to the invention and illustrated inFIG. 10 shows the transfer of several crystalline secondary structuresA1, A2, . . . , A7, A8, . . . , onto a support structure B. Thesecondary structures all originate from the same primary structure andtherefore all have the same orientation marks Va with the sameorientation with respect to their crystalline network. The orientationmarks Va are all similarly aligned on lines parallel to the supportstructure B. The parallel lines also comprise an orientation mark Vb ofthe support structure. The mutual crystalline alignment of the secondarystructures and their uniform twist angle means that they can be usedefficiently for epitaxy of an overlapping layer E that is partiallyshown. Note that in this example, the support structure B does notnecessarily have a crystalline part.

[0082] All secondary structures A1, A2 may have the same dimensions.They may be in a form that enables an overlap of the support structurewithout interstices. In the event, they are hexagonal secondarystructures.

[0083] Due to the transfer that maintains the crystalline orientation ofthe germs, and due to subsequent epitaxy, it is possible to obtain largediameter substrates with surface layers made of materials such as SiC orGaAs. For example, a substrate with a 200 mm diameter can be paved froma 35 mm diameter SiC monocrystal.

[0084] Variants of the embodiment of the process according to theinvention may include a step in which one or several secondarystructures are turned over. In particular, this makes it possible tochoose the face that will be put into contact with the support structureand the face that will be epitaxied, if any. The process may beiterated, using the structure resulting from the assembly as a newdonating structure or a new support structure. Intermediate steps may becarried out on it, for example such as material deposition and/orepitaxy, and/or polishing.

[0085] If the primary donating structures are sufficiently thick, thecrystalline orientations of each with respect to each other may bedetermined in advance, particularly using X-rays.

[0086] It is thus possible to control the crystalline orientations ofsecondary structures during successive transfers.

[0087]FIG. 11 shows the transfer of two secondary structures A1 and A2to a support structure B, in sequence. The two secondary structures A1and A2 originate from the same primary substrate A.

[0088] Subsequently, an additional secondary structure C1 originatingfrom another primary structure C is then transferred to the firstsecondary structure A1, that will then be used as a support structure.

[0089] Knowledge of the relative crystalline orientations of the primarystructures A and C makes it possible to control the relativeorientations of the secondary structures A1 and C1 according to theinvention.

Referenced Documents

[0090] (1) U.S. Pat. No. 5,374,564,

[0091] (2) K. Sakaguchi et al., 1999 IEEE International, SOI Conference,October 1999, p. 110

[0092] (3) F. Henley et al., European Semiconductor, February 2000, p.25

[0093] (4) FR-A-2 681472

[0094] (5) FR-A-2 748 850

[0095] (6) FR-A-2 748 851

[0096] (7) FR-A-2 781 082

[0097] (8) “Angular alignment for wafer bonding” Chou et al., SPIE, vol.2879, 1996, pages 291-299

[0098] (9) “Grazing Incidence, X-ray studies of twist-bonded Si/Si andSi/SiO₂ interface”, D. Buttard et al., PhysicaB, 283(1-3) (2000), P.103.

1. Process for controlling the orientation of secondary structures (A1,A2) with at least a crystalline part, during the transfer of secondarystructures from a primary structure (A) on which the secondarystructures have an initial crystalline orientation identical to theorientation of the primary structure or with a known misalignment withrespect to the primary structure, onto at least one support structure(B), the process comprising: a) the formation of at least oneorientation mark (Va, Va1, Va2) when the secondary structures are fixedto the primary structure (A), the mark having an arbitrary orientationwith respect to the said initial crystalline orientation, but allowingrelative orientation of the secondary structure, and b) when a set ofsecondary structures is transferred onto at least one support structure(B), an arrangement of the secondary structures so that theirorientation marks can be oriented in a controlled manner.
 2. Processaccording to claim 1, during a transfer of at least one secondarystructure from a primary structure (A) onto a support structure (B) withat least one crystalline part, in which step b) includes thedetermination of at least one offset angle of the crystallineorientations between the crystalline parts of the first secondarystructure (A1) and the support structure (B) after the transfer of atleast one first secondary structure (A1) onto the support structure (B)with an arbitrary arrangement of the orientation mark of the secondarystructure, and then when the subsequent secondary structures (A2) aretransferred, adjustment of the arrangement of the orientation marks as afunction of the determined offset angle.
 3. Process according to claim2, in which the offset angle is determined using a technique ofmeasuring interface dislocations between the secondary structure (Al)and the support structure (B) and/or a technique for using X-rays tomeasure an offset between the orientations of the crystalline parts. 4.Process according to either claim 1 or 2, in which at least oneorientation mark (Vb, Vb1, Vb2) is also formed on the support structure,and in which the orientation marks of the secondary structures areoriented with respect to the orientation marks of the support structure.5. Process according to claim 1, in which the orientation marks areformed using lithography and etching techniques.
 6. Process according toclaim 1, in which orientation marks are formed in the form of parallellines, verniers or squares.
 7. Process for manufacturing compositestructures comprising secondary structures (A, A1, A2) fixed to at leastone support structure (B), comprising: delimitation of secondarystructures (A1, A2) with at least one crystalline part in a primarystructure (A), and transfer of secondary structures onto a supportstructure (B) with at least one crystalline part, controlling therelative orientation of secondary structures and the support structurein accordance with any one of claims 1 to 6 process.
 8. Processaccording to claim 7, also comprising epitaxy of a layer (E) coveringall secondary structures bonded to the same support structure after thetransfer, the epitaxy using the crystalline part of each secondarystructure as a growth germ.
 9. Process according to claim 8, in whichepitaxy is used to form a layer extending at least partly onto asecondary structure and at least partly onto a support structure, inorder to form at least one grain boundary.
 10. Process according toclaim 7, in which the delimitation of secondary structures takes placeby cutting or by formation of a separation layer in the primarystructure.
 11. Process according to claim 7, in which the transfer stepcomprises the separation of at least one secondary structure (A1, A2)from the primary structure (A) and bonding of the secondary structureonto the support structure (B).
 12. Composite structure comprising afirst structure fixed to several second structures, characterised inthat at least one of the first and second structures has orientationmarks with uniform angular offsets.